Handle and trigger construction for one-hand portable tool



April 30, 1968 w. D. ABELL ET'AL 3,381,104

HANDLE AND TRIGGER CONSTRUCTION FOR ONE-HAND PORTABLE TOOL Filed Aug.29, 1966 WILLIAM D. ABELL JACK R. VEARA ATTORNEY United States Patent3,381,104 HANDLE AND TRIGGER CONSTRUCTION FOR ONE-HAND PORTABLE TOQLWilliam D. Abeli, Manchester, and Jack R. Veara, Sykesville, Md.,assignors to The Black and Decker Manufacturing Company, Towson, Md., acorporation of Maryland Filed Aug. 29, 1%6, Ser. No. 575,886 6 Claims.(Cl. 200-157) ABSTRACT OF THE DISCLOSURE The device disclosed herein isa portable, electric power tool including a housing having a hollow,depending, pistol-type handle. A control switch is mounted in the handleand is actuated by a one-piece, pivotal trigger detachably secured insnap-on fashion to the handle. The handle also has a detachable coverpermitting free access to the switch.

This invention relates generally to rotary power devices, andparticularly to an improved handle and trigger construction whichfacilitates one-hand" operation of portable, reversible or two-speedelectric power tools.

An important object of the present invention is to provide an improvedhandle and trigger construction for reversible or two-speed portable,electric power tools which construction facilitates true one-hand tooloperation and employs a minimum of individual parts.

Additional important objects of the present invention are to provide animproved handle and trigger construction of the above character whereinthe connection therebetween is effected by component portions integraltherewith and which portions togther with a reversing or speed controlswitch for the tool motor are concealed in assembly to provide anaesthetically pleasing device.

Further important objects of the present invention include the provisionof a handle and trigger construction of the above character which is ofprimary simplicity to assemble and disassemble, relatively inexpensiveto manufacture, rugged in construction and reliable in use.

Other objects and advantages of the present invention will become moreapparent from a consideration of the following detailed descriptiontaken in conjunction with the drawings in which:

FIG. 1 is a side elevational view illustrating a typical portableelectric power tool embodying the present invention;

FIG. 2 is an enlarged vertical sectional view of the handle and triggerstructure of FIG. 1;

FIG. 3 is an exploded view of the structure of FIG. 2;

FIG. 4 is a sectional view of FIG. 2 taken along the line 4-4 thereof;

FIG. 5 is a perspective view illustrating the trigger handle of thepresent invention;

FIG. 6 is a progressive illustration of the steps of assembly of thetrigger to the handle; and

FIG. 7 is a sectional view of FIG. 3 taken along the line 77 thereof.

Broadly described, the present invention includes an integral handleframe having laterally spaced side walls, a switch carried by saidhandle frame and having an actuating lever extending forwardly thereof,said side walls having a pair of opposed, arcuate cross-sectional bossesformed integrally thereon and projecting inwardly of said handle framefrom the inner surface of said side walls, respectively, a one-piecetrigger handle having laterally spaced side walls partially received insaid handle frame and closely disposed relative to said handle frameside walls, said trigger handle side walls having a pair of arcuateslots formed therein generally complementary to said bosses and adaptedto receive said bosses in smooth, pivotal relation, a pair of earsprojecting from each said trigger handle side wall and integraltherewith, each pair of cars defining an entry to a respective one ofsaid slots of a dimension less than the lateral dimension of saidbosses, said ears being adapted to guidingly receive and snap over saidbosses as said bosses move into said slots whereby to pivotally retainsaid trigger handle to said handle frame, and means interconnecting saidtrigger handle and said switch lever.

Referring now more specifically to the drawings, a reversible impactwrench, which is one typical device with which the present inventionfinds use, is illustrated generally at 11 in FIG. 1 and is seen toinclude a motor and transmission housing 13 having an end cover 15remova bly secured thereto at its rear end and a resilient bumper 17mounted on the forward end thereof. A suitable electric drive motor (notshown) or other drive source is positioned within the housing 13 and theend cover 15 has a pair of brush holders 19 (only one of which is shown)which carry brushes (not shown) engageable with the motor commutator(not shown) in the usual manner. The drive motor rotatably drives -atool bit (not shown) such as, for example, a nut socket through asuitable gear transmission (not shown) also located in the housing 13.Impact wrench drive mechanisms of this type are well known in the artand since this structure forms no part of the present invention, it isnot illustrated nor described further here. Reference, however, may bemade to the copending application Ser. No. 553,383, filed May 27, 1966under the name of George E. Malfey, Jr. et a1. and owned by the assigneeof the present application for a better understanding of this mechanism.

The housing 13 is provided with a dependent handle frame 21 which mayeither be integral with or otherwise suitably fixed to the housing 13.For example, the housing 13 and handle frame 21 may be integrally castaluminum, or they may be molded using a suitable plastic or glass fibermaterial as is customary. The handle frame 21 preferably is hollow inconstruction having spaced, generally parallel side walls 23, 25interconnected at their lower ends by a base 27.

A reversing switch 29 for the electric drive motor (not shown) ispositioned within and removably secured to the handle frame 21. Theswitch 29 is seen to include a switch body 31 provided with a threadedmounting stud 33 extending forwardly thereof. A strut 37 is formedintegral with the handle frame 21 bridging the side walls 23, 25 thereofand is provided with a central opening 35 which freely receives the stud33. A pair of lock nuts 39, 41 are threaded on the end of the stud 33 tosecure the switch body 31 to the strut 37 and the body 31 is angularlylocated by boss like projections 43, 45 formed integrally on the frameside walls 23, 25 which are positioned adjacent the switch body 31.

A power line cord 51 is provided with a mounting flange 53 adapted to bepartially received in a recess 54 in the handle frame 21 and the flange53 is remov ably held in place by a molded plastic rear handle cap 55.The handle cap 55 has an upper, curved portion 64 receivable in a recess66 in the housing 13 and the handle frame 21 has a rearwardly projectingboss 56 threadedly receiving a screw 57 extending through the cap 55'.The line cord 51 carries a pair of power leads 53, 59 adapted to beconnected to one of a pair of terminal connectors 69, 62 on the switch29 and to the electric drive motor (not shown), respectively. The otherof the terminal connectors 60, 62 is connected in use directly to thedrive motor (not shown) in the usual manner. The line cord 51 alsocarries a ground lead 61 adapted for connection directly to the handleframe 21.

The switch 29 preferably is of conventional toggle-type construction andis provided with a pivotal lever 63 extending forwardly through themounting stud 33. The lever 63' has three pivotal positions, i.e., aneutral off position illustrated in FIGS. 2-4, and upwardly anddownwardly pivoted on positions relative to the neutral position shown.The switch lever 63 is normally resiliently biased toward the neutraloff position and the upwardly and downwardly pivoted on positions can beused to provide forward and reverse motor and tool operation oralternatively, they can provide high and low speed unidirectionaloperation thereof.

A novel trigger handle 65 is provided to control pivoted positioning ofthe switch lever 63 and is seen to preferably be constructed ofone-piece, molded plastic material, for example, nylon, and has agenerally U-shaped cross-sectional configuration as seen in FIGS. 4 and5. The trigger handle 65 has a pair of side walls 67, 69 partly receivedbetween the handle from side walls 23, 25 and a front wall 71interconnecting the side walls 67, 69. The trigger handle 65 also has atop and bottom wall 68, 70 partly receivable in the handle frame 21 andclosely adjacent an upper frame wall '72 and the handle base 27respectively, and which together with the front and side walls thereofserve to conceal the switch 29 and protect the operator during tool use.

The side walls 67, 69 are provided with aligned arcuately shaped 'slots73, 75 adapted to pivotally receive a pair of bosses 85, 87 integrallyformed on the handle frame side walls 23, 25, respectively, and betweenwhich the strut 37 extends. A pair of ears 77, 79 extend rearwardly fromthe side wall 67 to either side of the slot 73 and are tapered outwardlyto snap over and hold the boss 85 within the slot 73. Similarly, anotherpair of ears 81, 83 extend rearwardly from the side wall 69 to eitherside of the slot 75 and are adapted to snap over and hold the boss 87 inthe slot 75.

The trigger handle 65 is formed with a boss 89 between and substantiallyaligned with the slots 73, 75 and the boss has a central recess 91adapted to snugly receive the switch lever 63. As shown, the switchlever 63 may be serrated to provide secure positioning thereof withinthe recess 91.

In use, when the trigger handle 65 is pivoted on the bosses 85, 87 tothe two positions illustrated by dot-dash lines in FIG. 2, the switchlever 63 is moved to its upward and downward pivoted on positions.Clockwise pivotal movement of the trigger handle 65, as seen'in FIG. 2,is limited by engagement between a projecting stop 93 on the triggerhandle and a curved shoulder 94 on the housing 13 while counterclockwisepivotal movement is limited by engagement between an end 96 of thetrigger bottom wall 70 and the handle frame boss 55. Thus, the triggerhandle 65 is prevented from pivoting to an extent where the switch 29might be damaged. The normal, spring biased neutral position of theswitch lever 63 holds the trigger handle 65 in the position shown infull lines in FIG. 2 when no pivoting force is applied thereto.

As described above, the trigger handle 65 is constructed to snap on andis held in place by the handle frame bosses 85, 87. Thus, to install thetrigger handle 65, the outwardly tapered ears 77, 79 and 81, 83 areplaced against the bosses 85, 87, respectively, as shown in the firstsequence of FIG. 6. Pressure is then applied to the trigger handle frontwall 71 and the ears 77, 79 and 81, 83 begin to flex outwardly as theymove past the bosses 35, 87 as illustrated in the second sequence andultimately, the bosses 85, '87 snap into the arcuate recesses 73, 75,respectively, as seen in the third sequence of the figure.

This construction obviates the need for pivot pins or the like to mountthe trigger handle 65 in place and provides a highly inexpensive, simpleand aesthetically pleasing handle and trigger construction. In addition,to service the switch 29, the trigger handle 65 is easily removable fromthe handle frame 21 simply by pulling the trigger handle outwardly withones fingers or by using a suitable tool, or, alternatively, the rearcap 55 can be removed and the trigger handle can be pushed out of thehandle frame 21. If the handle rear end cap 55 is removed from thehandle frame 21, the switch 29 can either be serviced in the handleframe 21 or easily removed therefrom if desired.

As shown best in FIGS. 2 and 3, the trigger handle front wall 71 isformed with upper and lower concave portions 95, 97 adapted for easilyfinger placement and trigger handle manipulation during use. Forexample, when it is desired to energize the tool for forward or highspeed operation, defending upon whether the tool is of the reversible ortwo-speed type, the operator grasps the upper trigger handle portiontightly with his forefinger and middle finger, for example, whilelightly holding the lower concave portion 97 with his last two fingers.This causes the trigger handle 65 to pivot in a clockwise directionabout the bosses 85, 87, as seen in FIG. 2, and swings the switch lever63 upwardly. On the other hand, when it is desired to reverse the toolor employ low speed rotation thereof, the operator shifts the pressureemphasis on the trigger handle 65 applying pressure with his last twofingers on the lower concave portion 97 while lightly holding the upperconcave portion 95 with his forefinger and middle finger. This causesthe trigger handle 65 to pivot in a counter-clockwise direction, as seenin the figure, and moves the switch lever 63 downwardly. To stop thetool, the operator relaxes his fingers and the switch spring returns theswitch lever 63 and the trigger handle 65 to the position shown in fulllines in FIG. 2. Alternatively, an exterior spring such as, for example,a leaf spring can be provided in the handle frame 21 and positioned toengage the trigger handle 65 and normally bias it to the position shownin full lines in FIG. 2.

It will be appreciated that manipulation and tool operation from off, toforward or high speed, to reverse or low speed is effected with one-handgripping pressure on the tool handle alone and without the need for theoperator moving this hand or bringing his other hand across his body.Thus, this construction provides for onehand tool operation and controlin the true sense of the word thereby making use of the tool easier andless tirne consuming.

vBy the foregoing, there has been disclosed an improved handle andtrigger construction calculated to fulfill the inventive objects setforth hereinabove, and while a preferred embodiment of the presentinvention has been illustrated and described in detail, variousadditions, substitutions, modifications and omissions may be madethereto without departing from the spirit of the invention asencompassed by the appended claims.

We claim:

1. A tool handle and trigger construction comprising an integral handleframe having laterally spaced side walls, a switch carried by saidhandle frame and having an actuating lever extending forwardly thereof,said side walls having a pair of opposed, arcuate cross-sectional bossesformed integrally thereon and projecting inwardly of said handle framefrom the inner surface of said side walls, respectively, a one-piecetrigger handle having laterally spaced side walls partially received insaid handle frame and closely disposed relative to said handle frameside walls, said trigger handle side walls having a pair of arcuateslots formed therein generally complementary to said bosses and adaptedto receive said bosses in smooth, pivotal relation, a pair of earsprojecting from each said trigger handle side wall and integraltherewith, each pair of ears defining an entry to a respective one ofsaid slots of a dimension less than the lateral dimension of saidbosses, said ears being adapted to guidingly receive and snap over saidbosses as said bosses move into said slots whereby to pivotally retainsaid trigger handle to said handle frame, and means interconnecting saidtrigger handle and said switch lever.

2. A construction as defined in claim 1 wherein said switch is of thetoggle-type, said trigger handle having a recess adapted to receive saidswitch actuating lever, whereby pivotal movement of said trigger handleis effective to pivot said lever.

3. A construction as defined in claim 1 wherein said bosses aregenerally circular in cross-section.

4. A construction as defined in claim 1 wherein said handle frameincludes a strut bridging said side walls and integral therewith, saidswitch being detachably secured to said strut.

5. A construction as defined in claim 1 which includes a one-piece capspanning said handle frame side walls opposite said trigger handle anddetachably secured thereto, said handle frame including a base bridgingsaid side Walls, said trigger handle extending substantially from thetop of said handle frame side walls to said base whereby said switch issubstantially completely enclosed.

6. A construction as defined in claim 1 wherein said handle frame isintegral with a tool housing, said trigger handle including stop meanscooperable with said housing and handle to limit pivotal movementthereof in both FOREIGN PATENTS 4/ 1935 Great Britain. 11/1938 GreatBritain.

5 ROBERT K. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Exam ner.

